不同时间交叉验证方法影响多变量序列异常检测效果,滑动窗口更优。
Temporal cross-validation impacts multivariate time series subsequence anomaly detection evaluation
- 对比滑动窗口与向前滚动法,评估异常检测性能差异。
- 滑动窗口在深度模型上提升中位数AUC-PR并降低结果波动。
- 低折数时重叠窗口更利于保留故障特征,适合流式数据评估。
多变量时间序列(MTS)异常检测需关注时间依赖性,尤其在故障检测场景中常见子序列异常。尽管时间序列交叉验证(TSCV)旨在保持时间顺序,其对分类器性能的影响仍不明确。本研究系统考察了不同TSCV策略对检测故障型异常的分类器精度-召回特性的影响。在多种验证划分配置和分类器类型(浅层学习与深度学习)下,比较了向前滚动(WF)与滑动窗口(SW)方法。结果表明,滑动窗口在深度架构中持续获得更高的中位数AUC-PR,并显著降低折叠间性能方差;同时,分类器泛化能力受时间分区数量与结构影响,重叠窗口在低折数时更有效保留故障特征。分类器级分层分析显示,随机森林(RF)在各类方案中表现稳定,而其他算法则表现出明显敏感性。研究揭示了基准测试中时间序列异常检测模型的TSCV设计重要性,为流式时间序列环境下评估策略选择提供指导。
原文摘要 · Abstract (English)
Evaluating anomaly detection in multivariate time series (MTS) requires careful consideration of temporal dependencies, particularly when detecting subsequence anomalies common in fault detection scenarios. While time series cross-validation (TSCV) techniques aim to preserve temporal ordering during model evaluation, their impact on classifier performance remains underexplored. This study systematically investigates the effect of TSCV strategy on the precision-recall characteristics of classifiers trained to detect fault-like anomalies in MTS datasets. We compare walk-forward (WF) and sliding window (SW) methods across a range of validation partition configurations and classifier types, including shallow learners and deep learning (DL) classifiers. Results show that SW consistently yields higher median AUC-PR scores and reduced fold-to-fold performance variance, particularly for deep architectures sensitive to localized temporal continuity. Furthermore, we find that classifier generalization is sensitive to the number and structure of temporal partitions, with overlapping windows preserving fault signatures more effectively at lower fold counts. A classifier-level stratified analysis reveals that certain algorithms, such as random forests (RF), maintain stable performance across validation schemes, whereas others exhibit marked sensitivity. This study demonstrates that TSCV design in benchmarking anomaly detection models on streaming time series and provide guidance for selecting evaluation strategies in temporally structured learning environments.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。